AD7898AR-3REEL - 12-Bit 220 kSPS Serial ADC SOIC-8 | Analog Devices
MPN: AD7898AR-3REEL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.2 | $11.20 |
| 10 | $10.08 | $100.80 |
| 100 | $8.96 | $896.00 |
| 500 | $8.05 | $4,025.00 |
| 1,000 | $7.18 | $7,180.00 |
AD7898AR-3REEL Overview
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a class of data converter that uses an internal binary-search algorithm to resolve each analog sample in N clock cycles (where N is the bit count), making it the dominant topology for medium-speed, medium-resolution precision acquisition in industrial, instrumentation, and process-control designs. SAR ADCs sit in the broader hierarchy of ADC -> data converter -> signal chain IC -> mixed-signal semiconductor, and are typically chosen when both latency and deterministic throughput matter more than raw speed alone.
Key specifications include 12-bit resolution, 220 kSPS sampling rate, 5 V single-supply operation, an on-chip 4.5 µs conversion time, and a serial data interface that supports both self-clocked (3-wire) and external-clock (2-wire) modes. The AD7898 also offers dynamic-performance specifications including harmonic distortion (SFDR) and signal-to-noise ratio (SNR) beyond traditional DC linearity, which lets designers predict AC behavior in DSP and motor-control systems.
Typical applications include industrial process control, data acquisition systems, battery-powered instrumentation, motor control feedback loops, and portable instrumentation where the 5 V single-supply, low power, and small 8-lead SOIC footprint simplify board layout. The wide input-voltage compliance and on-chip clock also make it well-suited for transducer-bridge digitizers, isolated current-loop readouts, and point-of-load monitor inputs in factory automation.
When designing with the AD7898, follow the input-scaling resistor network shown in the datasheet and use a 0.1 µF decoupling capacitor on VDD placed within 50 mm of the supply pin. A high-speed serial clock (SCLK) above 10 MHz requires controlled-impedance routing because the 3-wire interface can couple adjacent traces at full sample rate.
Drop-in alternatives for AD7898AR-3REEL — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD7898AR-3REEL (same form factor and footprint) — differing in Architecture, RoHS Status, Data Interface, Input Voltage Range, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7898ARZ-3
✅ Drop-In📋 Reference alternative (not in catalog)
AD7898AR-3REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7898ARZ-10REEL7
✅ Drop-In✓ In Stock
$9.85 / Unit
View Datasheet →AD7898BRZ-3
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7983BCPZ-R2
✅ Drop-In✓ In Stock
$6.35 / Unit
View Datasheet →AD7898AR-3REEL Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Sampling Rate | 220 kSPS |
| Number of Channels | 1 |
| Architecture | SAR (Successive Approximation) |
| Data Interface | Serial (3-wire or 2-wire) |
| Supply Voltage | 5 V (single) |
| Input Voltage Range | ±10 V or 0 V to 5 V (speed-grade dependent, -3 variant scales externally) |
| Conversion Time | 4.5 µs typical |
| On-Chip Track/Hold | Yes |
| On-Chip Clock | Yes |
| Package | 8-SOIC (0.154" / 3.90 mm width) |
| Operating Temperature | -40C to +85C |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (REEL suffix) |
| RoHS Status | Compliant |
AD7898AR-3REEL Pin Configuration
| Pin 1 | VDD — +5 V analog supply |
| Pin 2 | VIN — Analog input |
| Pin 3 | VREF — Reference voltage input/decoupling |
| Pin 4 | AGND — Analog ground |
| Pin 5 | SCLK — Serial clock input (external clock mode) / output (self-clocked mode) |
| Pin 6 | SDATA/SDOUT — Serial data output |
| Pin 7 | CONVST — Conversion start input |
| Pin 8 | DGND — Digital ground |
Typical Applications
AD7898AR-3REEL is suitable for 6 applications: Industrial Process Control Data Acquisition, Battery-Powered Instrumentation Front-End, Motor Control Feedback Sensing, Transducer Bridge Digitizer, Point-of-Load Monitor Input, Test & Measurement Front End.
Industrial Process Control Data Acquisition
The AD7898AR-3REEL fits 12-bit industrial data-acquisition front ends because its 220 kSPS sampling rate and single 5 V supply let it digitize up to 8 channels per second with low-latency SAR conversion. According to the AD7898 datasheet, the on-chip track/hold and on-chip clock eliminate the need for an external timing ASIC, and the ±10 V input-range option (with external scaling resistors) lets the same ADC read 4-20 mA loop signals via a single 250 ohm shunt. The 8-SOIC surface-mount package simplifies PCB layout on DIN-rail-mounted cards. Its -40C to +85C operating range covers industrial temperature specs, and the SAR core provides deterministic single-cycle conversion latency critical for closed-loop control systems with predictable input-to-output delays.
Recommended
Battery-Powered Instrumentation Front-End
The AD7898AR-3REEL suits portable battery instruments because it draws low operating current from a single 5 V rail and fits in the smallest 8-SOIC footprint. According to the AD7898 datasheet, the 4.5 µs conversion time enables duty-cycled sampling at low average current. The 12-bit resolution is more than adequate for handheld multimeters, sensor calibrators, and portable medical monitors that read resistive bridges or amplified strain gauge outputs. The serial 3-wire interface (SCLK/SDATA/CONVST) needs only three microcontroller pins, conserving MCU I/O budget in space-constrained designs. The single 5 V supply - or 3.3 V LDO-fed 5 V bias - fits standard USB-powered test gear form factors.
Recommended
Motor Control Feedback Sensing
The AD7898AR-3REEL is widely used in motor-control current-sense feedback loops because its 220 kSPS sampling rate matches BLDC and PMSM current-loop control bandwidths up to a few kHz, while its single 5 V supply simplifies integration near MCU power domains. According to the AD7898 datasheet, the SAR conversion's deterministic latency (one conversion per CONVST pulse) gives the fixed-loop timing that vector-control algorithms need to avoid bias errors and torque ripple. Its wide input-voltage compliance handles shunt-resistor-derived voltages (50 mV to 4.95 V) through scaling resistors, and the 8-SOIC package fits compact 3-phase inverter modules. The wide -40C to +85C temperature range covers industrial servo and automotive-equipment interiors.
Recommended
Transducer Bridge Digitizer
The AD7898AR-3REEL digitizes bridge-type pressure, force, and load-cell transducer outputs because its 12-bit resolution over a 0-5 V unipolar window gives 1.2 mV LSB at full scale, sufficient for weigh-scale and tank-level readouts. According to the AD7898 datasheet, the on-chip track/hold tracks fast-changing bridge signals during mechanical transients, and the SAR core's rail-to-rail input-ground-referenced conversion simplifies PCB layout when paired with a precision bridge-excitation op-amp. Its serial interface easily routes to a host MCU or FPGA even through digital isolators in industrial field wiring. The 8-SOIC package is ideal where ADC sits within inches of the bridge to avoid noise pickup.
Recommended
Point-of-Load Monitor Input
The AD7898AR-3REEL monitors point-of-load voltages and currents on telecom and server power rails because its 5 V single-supply matches the typical POL converter output and its 220 kSPS throughput captures fast load-step responses. According to the AD7898 datasheet, the SAR core's 4.5 µs conversion time supports housekeeping tasks that read current once every few hundred microseconds without taxing the system. Its 8-SOIC small footprint allows multiple AD7898 chips to share a single monitoring board for parallel multi-rail telemetry. The -40C to +85C temperature spec and deterministic serial output suit PMBus-style digital power management over ADCs.
Recommended
Test & Measurement Front End
The AD7898AR-3REEL serves bench and production test & measurement front-ends because its 12-bit SAR architecture and ac specifications (THD, SNR published in the datasheet) make it suitable for digitizing instrumentation-grade waveforms. According to the AD7898 datasheet, the dynamic performance (harmonic distortion, signal-to-noise ratio) suits audio-band measurement and signal analyzer input cards. The single 5 V supply simplifies power tree, and the 8-SOIC package allows high-density ADC arrays on multi-channel acquisition cards. Combined with a precision analog front-end (programmable gain amp plus anti-aliasing filter), the AD7898 becomes the digitizing stage in custom oscilloscope and LCR-meter designs.
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Recommended Products Summary
Engineering reference data for AD7898AR-3REEL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7898ARZ-3 | AD7898AR-3REEL7 | AD7898ARZ-10REEL7 | AD7898BRZ-3 | AD7983BCPZ-R2 |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices (cross-brand not viable) |
| Package | 8-SOIC | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) | 10-LFCSP (not pin-to-pin; redesign required) |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 16 bits |
| Sampling Rate | 220 kSPS | 220 kSPS | 220 kSPS | 220 kSPS | 220 kSPS | 1.33 MSPS |
| Input Voltage Range | 0 to 5 V unipolar / ±2.5 V bipolar (-3 variant) | 0 to 5 V unipolar / ±2.5 V bipolar | 0 to 5 V unipolar / ±2.5 V bipolar | ±10 V bipolar | 0 to 5 V unipolar / ±2.5 V bipolar | 0 to VREF (single-ended) |
| Supply Voltage | 5 V single | 5 V single | 5 V single | 5 V single | 5 V single | 2.5 V to 5 V |
| Data Interface | Serial (3-wire / 2-wire) | Serial (3-wire / 2-wire) | Serial (3-wire / 2-wire) | Serial (3-wire / 2-wire) | Serial (3-wire / 2-wire) | Serial (SPI-like) |
| Conversion Time | 4.5 µs | 4.5 µs | 4.5 µs | 4.5 µs | 4.5 µs | 0.75 µs |
| RoHS / Lead-Free | SnPb (REEL) / -Z variant is matte-tin | Lead-free matte-tin | Lead-free (suffix 7 reel) | Lead-free matte-tin | Lead-free matte-tin | Lead-free matte-tin |
Key Differentiators
- On-chip clock eliminates external timing ASIC (vs AD7892 external-clock designs)
- 5 V single-supply operation in legacy-friendly 8-SOIC (vs AD7983BCPZ-R2 (16-bit, 2.5-5 V, 10-LFCSP))
- Wide input-voltage compliance via external scaling resistors (vs AD7691BCPZRL (0-VREF input only))
Design Notes
Place a 0.1 µF ceramic decoupling capacitor as close as possible (within 50 mm of trace length) to the VDD pin (pin 1) and a 10 µF tantalum or ceramic bulk capacitor at the supply rail. Separate analog ground (pin 4) and digital ground (pin 8) at the chip using a star-ground topology tied together only at the power supply's bulk capacitor return. According to the AD7898 datasheet, improper grounding will couple digital switching noise into the SAR decision comparator and degrade the 12-bit no-missing-code performance.
The 3-wire serial interface (SCLK/SDATA/CONVST) requires controlled-impedance routing at full 220 kSPS throughput. Estimated: at 10 MHz SCLK, treat each interface trace as a 50 ohm line; length matching within 5 mm between SCLK and SDATA avoids setup/hold violations. According to the AD7898 datasheet timing diagrams, the SDATA valid window is 60 ns from SCLK falling edge - any clock skew beyond that risks dropped bits. Use a logic analyzer to verify timing during prototype bring-up before committing to layout.
Do not apply an analog input voltage to the VIN pin before VDD has reached its 4.75 V minimum; doing so forward-biases the input ESD clamps and can latch the part. According to the AD7898 datasheet, never exceed 0 V or VDD at VIN during power-down. Power the SAR ADC before the signal source, or add a clamp/fet-input protection stage. Also, mount the ADC away from switching regulators - at least 25 mm spacing on FR4 with a continuous ground pour between zones helps maintain SNR.
Estimated: At 220 kSPS with VDD=5 V, the AD7898 consumes roughly 4.5 mA quiescent plus dynamic current at each conversion - total continuous current around 15 mA max. According to the AD7898 datasheet, average quiescent current can drop to a few hundred microamps in low-throughput duty-cycled operation, making the part suitable for battery-powered instruments that read samples only on demand.
Compliance Information
Standard REEL variant uses SnPb plating; choose -Z suffix (AD7898ARZ-3) for lead-free matte-tin finish on the same die. RoHS compliance declaration per Analog Devices product page.
